I'm not sure this is possible, but I was wondering if Greek text could be set to display as majuscule script (that is, all upper-case) -- and, if possible, while even taking out spaces. Mostly just as a relatively easy way to get used to reading such things so I can practice for reading real manuscripts at some point .

As a general rule of thumb, the Accordance Module will replicate the print text as much as possible. For modern Greek New Testaments (e.g., eclectic editions of GBS), the rule of thumb is replicate the print version. Now, you say, what about the interface. Can't I change these by the power of Accordance? Yes and no. You can remove spaces in the preferences of your text (⌘T select advanced and remove spaces), but the preferences don't currently permit to convert to lower to upper.

A better option I believe is to beef up your GNT library. With the Codex modules (e.g., GNT-VAT, ALEX, etc.), the rule of thumb produced modules whose font is Sylvanus (which is a better font option for Uncial rendering). You can set the preferences to these texts so that you have a digital reproduction of the actual Codex (and throw in the images collection for not only a digital, morphologically tagged module, but images to examine carefully the scribes hand).

I can understand. Just to give you idea of what I described above looks like:
[attachment=2503:Screen Shot 2012-08-28 at 11.02.55 AM.png]

By the way, I started to read from Ms images in my last year of my Greek Major. Such an experience changed a great deal of my understandings of scribal work and habits (which was a lot of fun since I am a digital scribe of sorts).